1. FIELD OF THE INVENTION
The present invention relates to an accessory for a vacuum cleaner wherein the vacuum cleaner has a vacuum source and an inlet tube or the like ending in a chamber. The inlet tube communicates with a nozzle opening and is normally connected to a dust container. The chamber having an opening which is normally covered by a lid. The accessory is a separate unit which can be removably fixed to the vacuum cleaner. The separate unit includes a cyclone separator that is shaped so that its inlet side can be connected to the inlet tube.
2. DESCRIPTION OF RELATED ART
Vacuum cleaners are commonly classified as either upright-type vacuum cleaners or a canister-type vacuum cleaners. Upright vacuum cleaners usually are provided with a lower, wheel supported part having a brush roll which is placed at the nozzle opening and drive means for the brush roll. The lower part of the vacuum cleaner is, by means of a link mechanism, connected to an upper part, which includes a chamber for a dust container. An upper portion of the upper part is shaped as a handle by means of which the vacuum cleaner is guided on the floor. The vacuum source, which usually comprises an electrically driven fan unit, may be placed in either the upper part or the lower part.
Canister vacuum cleaners comprise a shell enclosing a motor-fan unit and a chamber in which a dust container is disposed. An inlet tube ending in the chamber is, for this type of vacuum cleaner, connected to a nozzle opening of a separate cleaning nozzle by means of a hose.
It is previously known to integrate cyclone separators with conventional canister-type vacuum cleaners, see for instance EP-A-489468. These integrated or combined canister vacuum cleaners, however, suffer from the disadvantage that the size of the vacuum cleaner increases since there is a demand for a container for the conventional filter bag and also a container for the material separated by the cyclone separator.
Cyclone vacuum cleaners of the upright type have also been developed, see for instance EP-B-489565. In these vacuum cleaners, the upper part is shaped as a cyclone separator forming an integrated part together with the motor-fan unit whereby at least heavier particles are separated from the air by the cyclone and fall down into a collecting container from which they may be manually removed. This type of vacuum cleaner has certain disadvantages: large flow resistance with accompanying demands for larger power of the electric motor of the vacuum source in order to achieve the same suction efficiency in the nozzle part as a conventional vacuum cleaner; unhygienic emptying of the dust container; and, high production costs. However, a cyclone separator may be advantageous for certain cleaning tasks. For example, a cyclone separator might be useful when it is desirable to pick up large volumes of easily separable material, such as coarse sand, and in circumstances wherein the consumption of dust containers in a conventional vacuum cleaner would be large.
Thus, it has been suggested, see SE 9504682-7, to use an accessory by means of which the vacuum cleaner can be simply converted from a conventional vacuum cleaner with a dust bag into a cyclone vacuum cleaner so that the vacuum cleaner can be adapted to the material to be removed from the floor.
However, the arrangement shown in the lastmentioned publication has a disadvantage since emptying and cleaning of the accessory is troublesome because the cyclone, a coarse separator connected to the cyclone, air channels, filters and container are combined into one single unit whose inner parts are solely accessible from an opening at the bottom of the containers. Accordingly there exists a need in the art for a cyclone separator accessory that is easy to empty and clean.